Greetings,
I recently purchased a pair of Velleman VMA 301 Real Time Clock boards. I also purchased a VMA 202 Data logging shield which also has a real time clock. I noticed that I could not get the real time clock portion to run. The SD portion of the data logging shield does in fact work and is able to log data. However the Real time clocks do not respond. I used some code that I have successfully tested using the Adafruit data logging board and I could not get it to work. So I removed the DS1307 chip and used my Multi-meter to ohm out the board. What I discovered is that the layout of the board is incorrect. The pinout of the DS1307 according to the MAXIM data sheet is as follows: 1 (X1), 2(X2), 3(VBAT), 4(GND), 5(SDA), 6(SCL), 7(OUT), 8(VCC). What I found on the Velleman kit is as follows: 1(VCC), 2(X1), 3(X2), 4(GND), 5(RST), 6(SDA),7(SCL),8(VBAT). The crystal is not connected correctly the battery is installed on the Vcc and Gnd line. Pretty much nothing is connected correctly. It is totally botched. I could not decipher what happened. Possibly it was layed out for a different chip. Please correct the issue. I like the velleman boards and would like to see more. Don’t forget there is something wrong on the real time clock of the data logging shield also.
Thank You